Device for the transport of workpieces within a multi-stage press

ABSTRACT

A device for transporting workpieces within a multi-step press with a transverse crossbeam for holding the workpiece. The transverse crossbeam is aligned in its non-operative state at least approximately perpendicularly to the transporting direction of the workpieces. The crossbeam can be oriented in space by at least one driving mechanism. In addition, a second, redundant driving mechanism can be provided to move the transverse crossbeam in an emergency operation.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is related to and incorporates by reference herein U.S. patent application Ser. No. 10/025,984, filed Dec. 26, 2001, entitled Multistation Press, U.S. Patent No. pending.

BACKGROUND OF THE INVENTION

[0002] This application claims the priority of German patent application No. 101 57 328.6, filed Nov. 23, 2001, the disclosure of which is expressly incorporated by reference herein.

[0003] The present invention relates to a device for transporting workpieces within a multi-step press of the type for transporting workpieces and having a transverse crossbeam.

[0004] A known transporting or shifting device for converting machines or multi-step presses is described in DE 44 18 417 A1. In spite of numerous different advantages of transporting workpieces by transverse crossbeams, the problem can arise that, in the event of a breakdown of the driving mechanisms for the transverse crossbeams, there can be collisions. Thereby, the transverse crossbeam itself and also the rams, the tool mounted thereon and the workpiece, transported in the multi-step press, can be damaged, because the workpiece is transported by the transverse crossbeam completely independently of the processing of the workpiece.

[0005] EP 0 849 014 B1 describes a method for connecting a transfer device for the transport of workpieces along several work stations in an emergency type of operation, several direct electric driving mechanisms being provided for driving a transfer rail. In the emergency type of operation, a control device disconnects the power to the direct driving mechanism affected by the breakdown and continues to drive the remaining direct driving mechanism. This ensures that the transfer rail is taken out of the work stations.

[0006] However, the known procedure cannot be applied for a device of this type, because the transverse crossbeam, as already mentioned above, is moved completely independently of the driving mechanism of the ram. Thus, the further operation of one or more of the remaining driving mechanisms cannot ensure that the transverse crossbeam, the driving mechanism of which is affected by the breakdown, can be removed from the area of danger.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a device for transporting workpieces within a multi-step press, for which, even in the event of a breakdown of the driving mechanisms, any damage to the transporting device or the press or its parts is prevented.

[0008] This object has been accomplished by providing that, additionally to the at least one driving mechanism, a second, redundant driving mechanism is provided for moving the transverse crossbeam in an emergency operation.

[0009] In the event of a breakdown of a driving mechanism, the at least one redundant driving mechanism, which is provided pursuant to the invention, advantageously enables the transverse crossbeam to be operated further in an emergency operation, so that this transverse crossbeam can also continue to be operated further, at least for a short time synchronously with the ram and collisions of the parts, belonging to the transporting device, such as the transverse crossbeam, with the parts necessary for processing the workpiece, such a the ram, can be prevented.

[0010] Alternatively, an escape movement alone of the transverse crossbeam, brought about by the driving mechanism of the redundant driving mechanism, is also contemplated. For this escape movement, the transverse crossbeam can be moved into a position that is secure with regard to possible collisions with the ram.

[0011] Both possibilities can be converted into practice, so that the first driving mechanism and the second driving mechanism each are capable of such a performance, and each can be used by itself during the emergency operation of the transverse crossbeams.

[0012] Moreover, the performance of the two driving mechanisms can be dimensioned relatively low, so that a relatively inexpensive solution is provided which is, however, adequate for most of the intended applications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

[0014]FIG. 1 is a schematic view of a multi-step press with several inventive transporting devices disposed therein;

[0015]FIG. 2 is a schematic view of a transverse crossbeam disposed over a lever arrangement at a vertical guiding element of the transporting device;

[0016]FIG. 3 is a schematic view of a driving mechanism for the transporting device in a first embodiment of the present invention; and

[0017]FIG. 4 is a schematic view of a driving mechanism for the inventive transporting device of a second embodiment according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 shows a multi-step press designated generally by numeral 1, which, in the present illustration, has three individual steps 1 a, 1 b, and 1 c, as well as three rams 2, which can be moved up and down and at which tools 3 are mounted for molding workpieces 4 into any shape. The workpieces 4 are transported by several transporting devices 5 from one of the steps 1 a, 1 b and 1 c to the next step in 1 a, 1 b and 1 c. Of course, a completely different number of steps can also be provided for the multi-step press 1.

[0019] In the illustrated press, the transporting device 5 has two transverse crossbeams 6 for transporting the workpieces 4. The crossbeams 6 are disposed between the steps 1 a, 1 b and the steps 1 b, 1 c, and are intended for holding the workpieces 4 which, in their state of rest, are aligned approximately perpendicularly to the transporting direction of the workpieces 4 shown by arrow “T”. The construction of a transverse crossbeam 6, which enables a so-called modular transfer, is described in more detail with reference to FIG. 2.

[0020] The transverse crossbeam 6 is in each case mounted by way of a lever arrangement 7 at both its ends at a vertically extending guiding element 8 as part of the transporting device 5. In the present case, only the end 6 a of the transverse crossbeam 6 and consequently only its mounting at the guiding element 8 is shown. The lever arrangement 7 allows the transverse crossbeam 6 to be oriented at will in space, especially in regard to different heights of the two ends.

[0021] For this purpose, the lever arrangement 7 has a main lever 7 a which is mounted rotatably with respect to the vertical guiding element 8 and is held by three driving and connecting levers 7 b, 7 c and 7 d at the guiding element 8. Of course, one skilled in the art will know that there is an identical mirror-image arrangement of levers 7 at the end of the transverse crossbeam 6 opposite to the end 6 a, so that the transverse crossbeam 6, which additionally can be rotated relative to the main lever 7 a, can be oriented practically at will in space.

[0022] In FIG. 3, two driving mechanisms 9, 10 are shown schematically for the respective levers 7 b, 7 d. Consequently, these driving mechanisms 9, 10 can move the two levers 7 b and/or 7 d independently of one another. The main lever 7 a is swiveled by two levers 7 b, 7 d due to the fact these two levers engage a transfer-of-forces point 7 e and swivel the main lever 7 a about a fulcrum 7 f, at which the main lever 7 a is mounted at the guiding element 8. Thereby, the transverse crossbeam 6 is enabled to move in approximately any direction.

[0023] A redundant, that is, an additional driving mechanism 11 or 12, is assigned to each of the respective driving mechanisms 9 or 10 here. As shown in FIG. 3, all driving mechanisms 9, 10, 11 and 12 are linear direct driving mechanisms, the mode of action of which, in principle, is known and therefore is not explained in greater detail.

[0024] The driving mechanism 9 and the redundant device 11, which is assigned to the driving mechanism 9, have a common secondary part 13, on which two primary parts 9 a, 11 a are movably disposed. In the same way, the driving mechanisms 10, 12 also have a common secondary part 14, on which two primary parts 10 a, 12 a are movably disposed. The primary parts 9 a, 11 a, as well 10 a, 12 a, are each connected mechanically with one another and have the same command signal, for example, the movement of the ram 2, although they can be selected independently from one another within the scope of the present invention. Alternatively to the version shown, the driving mechanisms 9, 11 as well as 10, 12, can also have common primary parts and, in each case, two secondary parts.

[0025] A slide 15 is connected mechanically with the driving mechanisms 9, 11, and a slide 16 is connected mechanically with driving mechanisms 10, 12. The slide 15 is mounted at the lever 7 b, and slide 16 is mounted at the lever 7 d. In this way, the slides 15, 16 can be moved on an assigned guide rail 17 or 18, respectively, both of which are disposed on the guiding element 8. In this way, the two levers 7 b, 7 d can be shifted which, in turn, leads to a shifting of the transverse crossbeam 6, as described above.

[0026] The two driving mechanisms 9, 11 as well as 10, 12, which belong together, can jointly effect the normal operation of the transverse crossbeam 6, i.e., they have sufficient power for jointly moving the transverse crossbeam 6 in all operating situations. In the event that one of the driving mechanisms 9, 11 or 10, 12 fails, an emergency operation of the transverse crossbeam 6 is then still possible with the remaining driving mechanism 11, 9 or 12, 10, in that these are moved, for example, to a point at which the workpieces 4 rest on the tools 3. Thereby, there is no longer any danger of collision within the multi-step press 1. In this state, the transverse crossbeam 6 is also removed from the domain of influence of the ram 2. In the event that one of the driving mechanisms 9, 10, 11 or 12 fails, it is freed from advancing forces.

[0027] A generally known controlling system of the multi-step press 1 (not shown) can be configured to be switched over appropriately in the event of a breakdown of the driving mechanisms 9-12 and automatically adapt the outputs of the driving mechanisms 9-12 required for this purpose based upon the foregoing construction.

[0028] Alternatively, only the driving mechanisms 9, 10 can be intended for the normal operation of the transverse crossbeam 6. That is, each, for itself, should then have a sufficiently high power to operate the transverse crossbeam 6 in any operating state. The two redundant driving mechanisms 11, 12 could then be engaged only in an emergency operation and also have sufficient power to operate the transverse crossbeam 6, so that the latter can also be operated in the accustomed manner in the event of a failure of one of the driving mechanisms 9 or 10 which are intended for the normal operation.

[0029] Of course, it is also contemplated that the driving mechanisms 11, 12 can be supplied with less power than the driving mechanisms 9, 10, so that only an emergency operation, optionally with a lesser overloading of the driving mechanisms 11 and 12, is possible.

[0030] In principle, three different types of emergency operations are now achievable, i.e., the “escape” of the transverse crossbeam 6 into the next possible safe position, the synchronous operation between the transverse crossbeam 6 and the ram 2 up to the shutting down of the multi-step press 1, and the moving of the transverse crossbeam 6 to the end of a working cycle. One of these options is selected, depending on the configuration of the driving mechanisms 9-12 as well as on the nature of the multi-step press 1 and the workpieces 4.

[0031]FIG. 4 shows the two driving mechanisms 9, 11 for driving the slides 15. The two driving mechanisms 9, 11 are constructed here as rotating electric motors, which act with their respective rotors 19, 20 on a transmission 21 and, with that, on the slide 15. Once again, the driving mechanism 9 is intended for the normal operation of the transverse crossbeam 6, and the driving mechanism 11 is constructed as a redundant driving mechanism for the emergency operation of the transverse crossbeam 6. The comments, already made above for the linear direct driving mechanisms, also apply with regard to the respective performance and manner of operation of the two driving mechanisms 9, 11 and, with that also, with regard to the performance of the transverse crossbeam in the event of an emergency operation, in the event of a breakdown of one of the two driving mechanisms 9 or 11, the latter becoming torque-free.

[0032] Alternatively, the two driving mechanisms 9, 11 can also have a common rotor 22, on which two mutually independent stators 9 b, 11 b are mounted, as indicated by the dashed lines. In this embodiment, it is optionally possible to do without the transmission 21. The driving mechanisms 10, 12 can, of course, also be constructed in the same manner as the driving mechanisms 9, 11 in such an embodiment.

[0033] The above-mentioned twisting of the transverse crossbeam 6 can be initiated over a further driving mechanism 23, which can be disposed in the fulcrum 7 f and the rotational movement of which is transferred to the transverse crossbeam 6 by cogged belts and the like disposed within the main lever 7 a. The driving mechanism 23 can also be provided with a redundant driving mechanism.

[0034] Moreover, it is optionally contemplated to do without the lever arrangement 7 and to drive the entire transverse crossbeam 6, i.e., to swivel it about the fulcrum 7 f, with the driving mechanism 23 configured correspondingly to do so. For this purpose also, a redundant driving mechanism can be provided in the sense described above. Moreover, in this case, a further driving mechanism 24 fully rotating the transverse crossbeam 6 can be provided in the region of the end 6 a of the transverse crossbeam 6 within the main lever 7 a. This can also be provided with a redundant driving mechanism within the scope of the present invention.

[0035] The construction of the driving mechanisms 9-12 can, of course, be employed for all transverse crossbeams 6 of the multi-step press 1 which operate completely independently of one another.

[0036] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

1. A device for transporting workpieces within a multi-step press having a transverse crossbeam to hold the workpiece, to be aligned in a non-operative state thereof at least approximately perpendicularly to a transporting direction of the workpieces and configured to be oriented by at least one first driving mechanism, and a second, redundant driving mechanism is provided for moving the transverse crossbeam in an emergency operation.
 2. The device of claim 1, wherein the at least one first driving mechanism and the second driving mechanism each are configured such that each can be used, by itself, for the emergency operation.
 3. The device of claim 1, wherein the at least one first driving mechanism and the second driving mechanism are linear direct driving mechanisms.
 4. The device of claim 3, wherein the at least one first driving mechanism and the second driving mechanism have a common secondary part and two primary parts that are independent of and interact with one another.
 5. The device of claim 1, wherein the at least one first driving mechanism and the second driving mechanism are rotating electric motors.
 6. The device of claim 5, wherein the electric motors have a common rotor and stators that are arranged independently of one another.
 7. The device of claim 5, wherein the electric motors have mutually independent rotors with associated stators and are connected over a transmission with the transverse crossbeam.
 8. The device of claim 1, wherein each driving mechanism of the transverse crossbeam is provided with an additional, redundant driving mechanism.
 9. The device of claim 1, wherein the transverse crossbeam is operatively held at two ends thereof by levers, at least two of the levers being driveable by at least one first and second driving mechanism.
 10. A multi-step press with at least one device for transporting workpieces according to claim
 1. 11. A multi-step press according to claim 10, wherein the at least one first driving mechanism and the second driving mechanism each are configured such that each can be used, by itself, for the emergency operation.
 12. A multi-step press according to claim 10, wherein the at least one first driving mechanism and the second driving mechanism are linear direct driving mechanisms.
 13. A multi-step press according to claim 12, wherein the at least one first driving mechanism and the second driving mechanism have a common secondary part and two primary parts that are independent of and interact with one another.
 14. A multi-step press according to claim 10, wherein the at least one first driving mechanism and the second driving mechanism are rotating electric motors.
 15. A multi-step press according to claim 14, wherein the electric motors have a common rotor and stators that are arranged independently of one another.
 16. A multi-step press according to claim 14, wherein the electric motors have mutually independent rotors with associated stators and are connected over a transmission with the transverse crossbeam.
 17. A multi-step press according to claim 10, wherein each driving mechanism of the transverse crossbeam is provided with an additional, redundant driving mechanism.
 18. A multi-step press according to claim 10, wherein the transverse crossbeam is operatively held at two ends thereof by levers, at least two of the levers being driveable by at least one first and second driving mechanism. 